A semiconductor device is provided by: mounting semiconductor chips on, for example, a lead frame (or a base material); electrically connecting electrodes (bonding pads) of the semiconductor chips and the lead frame to one another by wires; and then packaging them, various circuit blocks being formed on the semiconductor chips. The packaging is carried out by partially sealing the lead frame with, for example, a resin by using a molding device, the semiconductor chips being mounted on the lead frame.
In the molding device, the lead frame on which the semiconductor chips are mounted is sandwiched between an upper mold and a lower mold that are respectively heated, and the upper mold and the lower mold are tightened by a presser. In a main surface of the upper mold and a main surface of the lower mold that is opposed to the main surface of the upper mold, cavity parts having respectively predetermined shapes are formed, and the lead frame is disposed between the upper and lower molds so that the semiconductor chips are located at the cavity parts. Moreover, when the molds are tightened, the resin is injected so as to fill the cavity parts. Thus, the semiconductor chips and a portion of the lead frame (tab or the like) on which the semiconductor chips are mounted are sealed with a resin having predetermined shapes, and provided as a semiconductor device that has been packaged.
Such a molding device has been disclosed by, for example, Patent Document 1 (Japanese Patent Application Laid-open No. H9-123183). Incidentally, in Patent Document 1, this molding device is referred to as a “transfer molding device”.